An observation of global diflufenican registration and type of formulations

Diflufenican is a pyridinecarboxamide herbicide used on corn, soybean and wheat fields for controlling annual grassy weeds and some broadleaf weeds.

In general, diflufenican is used for pre-emergence and post-emergence applications on autumn wheat and barley fields for controlling grassy weeds and broadleaf weeds. Europe is the main market for diflufenican, with France, Germany and the UK, as well as Australia, being its largest markets.

From a market application perspective, diflufenican is mainly intended for application on grains, with specific use in other crops. However, in the European Union (EU) market, its registration increasingly covers precision production, where companies such as Bayer have continued to introduce new diflufenican mixture products. In Colombia, diflufenican has been successfully applied on rice. In the US, Bayer is preparing to launch new products in 2023. Such a market dynamics has empowered the development of the diflufenican industry and greatly extended the lifecycle of this traditional product.

Based on the market distribution of diflufenican, this paper offers an observation of the product’s registrations  in the EU, Australia, Argentina, Colombia and China.

1) European Union

According to the EU EFSA November 2007 resolution, the minimum content for diflufenican technical is 970g/kg. According to the document, although the product impurity of MakhshimAgan (ADAMA) differs from that of Bayer, neither of their product impurities are toxicological. In 2018, the EU issued a notice on the re-evaluation of diflufenican, which has not yet been completed. However, diflufenican is currently included in the EU’s Candidate for Substitution, with certain future regulatory risks.

Considering current registration approvals in Europe, the future registration trend could be as follows:

(1) Conventional registration will be mostly 500g/L SC and 50% WDG single agent, as well as a flufenican+diflufenican mixture.

(2) New registrations will be mostly mixtures – (a) Mixture with existing major conventional active ingredients, such as pendimethalin, glyphosate and prosulfocarb. After the above active ingredients have been recently re-evaluated by the EU, mixtures are expected to improve the performance of the formulations. However, the crops for application will be the same as those where the major active ingredients have been applied previously; (b) Trials for the registrations of new combinations for new crop applications, such as a mixture with penoxsulam for application on rice, a mixture with iodosulfuron-methyl for application on oats, and a mixture with metsulfuron-methyl and chlortoluron; (c) Diversified grain-oriented formulations developed by multinational companies, such as Bayer and ASCENZA.

(3) Conventional formulations will still be subject to major registrations and promotions; the registration and promotion of multinationals’ novel formulations are done to distance themselves from generic producers.

It is worthy of note that formulation registrations in Germany and France do not usually include formulations granted via technical equivalence. In most cases, generic manufacturers need to independently develop their own formulations (consistent formulation).

2) Australia

Registered formulations in Australia are significantly different from those in Europe. As well as a conventional single agent, diflufenican formulations registered in Australia are mainly mixtures with bromoxynil octanoate and agroxone, while common European mixtures with flufenacet do not exist in Australia, which indicates that diflufenican is positioned as a product for upgrading conventional wheat herbicides and resistance management down under.

Currently, there are 21 diflufenican technical registrations in Australia

Table1    Traceable Diflufenican Technical in Australia

3) Argentina

Up to December 2022, seven diflufenican technical registrations were granted in Argentina.

Table2   Diflufenican Technical Registrations in Argentina until December 2022

The registered formulations in Argentine are almost all 500g/L SC single agents being held by large distributors in Argentina, with only a few companies, such as Rotam, holding 50% WDG registrations.

4) Columbia

Colombia is the only country where diflufenican is not primarily used on wheat crops. All registrations are filed for 500g/L SC or 50% WDG single agent, which are intended for application on rice. The registrants are mostly local distributors, which is a significantly different situation from Europe.

From the perspective of date of registration and renewal status, the registration and promotion of diflufenican in the Colombian market appear positive and active.

Currently, there is has been no diflufenican registration and market release in the US. According to media, from 2023 to 2024, Bayer may launch diflufenican in the North American market, targeted at soybean and corn, which are different from current mainstream grains worldwide. Special attention needs to be paid to the future registration and type of formulations of diflufenican in the US.

5) China

In December 2022, there were 13 diflufenican technical registrations in China.

Table 3   Diflufenican Technical Registrations in China

There are now more registrations of diflufenican formulations, including 17 single agents, being mostly diflufenican 30%/41%, 500g/L SC, diflufenican 50% WDG, diflufenican 50% WP and diflufenican15% OD.

There are 26 mixture registrations which are used for winter wheat, including diflufenican 5%+isoproturon 50% SC (most registrations are combinations of diflufenican with various ipraturon), diflufenican 11%+ (flufenacet 11%+flurtamone 11% SC (Bayer), diflufenican 11.7%+flufenacet 23.3% SC, diflufenican 15%+florasulam 1% SC, and isoproturon 60%+diflufenican 11%+pinoxaden 4% WDG. Products which are used for paddy rice include diflufenican 3%+pendimethalin 33% SC, and diflufenican 63%+ pyrazosulfuron-ethyl 7% WDG. Product that are used for garlic field include diflufenican 11%+oxyfluorfen 22% SC.

Registrations in China show that the registration of diflufenican technical is largely stable, with little possibility of newcomers registering the product. However, the registration of formulations is highly diverse, being mostly wheat field herbicides, while rice and precision herbicide applications are possible. Registration in China is basically consistent with the worldwide diflufenican market distribution.